To investigate the relationship between farming exposures and asthma, we have developed a case-cohort study within a large cohort of farmers -- the Agricultural Health Study. This study follows up findings regarding the association between correlates of exposure to pathogen associated molecular patterns (such as endotoxin) and various questionnaire-based asthma and atopy phenotypes. It is also designed to follow-up findings based on questionnaire data of positive associations between pesticide exposures, especially organophospates, and questionnaire-based asthma phenotypes. To confirm and better understand these associations, objective measures of asthma and atopy phenotypes are needed along with more detailed exposure assessment. This study builds upon the Agricultural Health Study, a large cohort of farmers and their spouses in Iowa and North Carolina. We identified presumptive cases of asthma and non cases from the third phase of cohort follow-up and made home visits on eligible subjects. The Lung Health Study was launched on Feb 4, 2009. Field work ended September 30, 2013 and telephone interviews ended on November 15, 2013. We completed home visits with 3,255 people and 3,200 (98%) completed telephone interviews following their home visit. Pulmonary function was measure at home visit and blood was analyzed for a panel of 10 specific IgEs. Endotoxin was measured on over 2500 subjects. In the past year we have contributed to genome wide meta-analyses of pulmonary function. We have also submitted manuscripts in which we found early life farming exposure to be associated with reduced risk of atopy in adulthood. In another submitted manuscript we find house dust endotoxin to be related to asthma but not atopy.